| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| */ |
| |
| package freemarker.template.utility; |
| |
| import java.math.BigDecimal; |
| import java.math.BigInteger; |
| |
| /** |
| * Number- and math-related utilities. |
| * |
| * @since 2.3.20 |
| */ |
| public class NumberUtil { |
| |
| private static final BigDecimal BIG_DECIMAL_INT_MIN = BigDecimal.valueOf(Integer.MIN_VALUE); |
| private static final BigDecimal BIG_DECIMAL_INT_MAX = BigDecimal.valueOf(Integer.MAX_VALUE); |
| private static final BigInteger BIG_INTEGER_INT_MIN = BIG_DECIMAL_INT_MIN.toBigInteger(); |
| private static final BigInteger BIG_INTEGER_INT_MAX = BIG_DECIMAL_INT_MAX.toBigInteger(); |
| |
| private NumberUtil() { } |
| |
| public static boolean isInfinite(Number num) { |
| if (num instanceof Double) { |
| return ((Double) num).isInfinite(); |
| } else if (num instanceof Float) { |
| return ((Float) num).isInfinite(); |
| } else if (hasTypeThatIsKnownToNotSupportInfiniteAndNaN(num)) { |
| return false; |
| } else { |
| throw new UnsupportedNumberClassException(num.getClass()); |
| } |
| } |
| |
| public static boolean isNaN(Number num) { |
| if (num instanceof Double) { |
| return ((Double) num).isNaN(); |
| } else if (num instanceof Float) { |
| return ((Float) num).isNaN(); |
| } else if (hasTypeThatIsKnownToNotSupportInfiniteAndNaN(num)) { |
| return false; |
| } else { |
| throw new UnsupportedNumberClassException(num.getClass()); |
| } |
| } |
| |
| /** |
| * @return -1 for negative, 0 for zero, 1 for positive. |
| * @throws ArithmeticException if the number is NaN |
| */ |
| public static int getSignum(Number num) throws ArithmeticException { |
| if (num instanceof Integer) { |
| int n = num.intValue(); |
| return n > 0 ? 1 : (n == 0 ? 0 : -1); |
| } else if (num instanceof BigDecimal) { |
| BigDecimal n = (BigDecimal) num; |
| return n.signum(); |
| } else if (num instanceof Double) { |
| double n = num.doubleValue(); |
| if (n > 0) return 1; |
| else if (n == 0) return 0; |
| else if (n < 0) return -1; |
| else throw new ArithmeticException("The signum of " + n + " is not defined."); // NaN |
| } else if (num instanceof Float) { |
| float n = num.floatValue(); |
| if (n > 0) return 1; |
| else if (n == 0) return 0; |
| else if (n < 0) return -1; |
| else throw new ArithmeticException("The signum of " + n + " is not defined."); // NaN |
| } else if (num instanceof Long) { |
| long n = num.longValue(); |
| return n > 0 ? 1 : (n == 0 ? 0 : -1); |
| } else if (num instanceof Short) { |
| short n = num.shortValue(); |
| return n > 0 ? 1 : (n == 0 ? 0 : -1); |
| } else if (num instanceof Byte) { |
| byte n = num.byteValue(); |
| return n > 0 ? 1 : (n == 0 ? 0 : -1); |
| } else if (num instanceof BigInteger) { |
| BigInteger n = (BigInteger) num; |
| return n.signum(); |
| } else { |
| throw new UnsupportedNumberClassException(num.getClass()); |
| } |
| } |
| |
| /** |
| * Tells if a {@link BigDecimal} stores a whole number. For example, it returns {@code true} for {@code 1.0000}, |
| * but {@code false} for {@code 1.0001}. |
| * |
| * @since 2.3.21 |
| */ |
| static public boolean isIntegerBigDecimal(BigDecimal bd) { |
| // [Java 1.5] Try to utilize BigDecimal.toXxxExact methods |
| return bd.scale() <= 0 // A fast check that whole numbers usually (not always) match |
| || bd.setScale(0, BigDecimal.ROUND_DOWN).compareTo(bd) == 0; // This is rather slow |
| // Note that `bd.signum() == 0 || bd.stripTrailingZeros().scale() <= 0` was also tried for the last |
| // condition, but stripTrailingZeros was slower than setScale + compareTo. |
| } |
| |
| /** |
| * Tells if the type of the parameter number is known to not be able to represent infinite (positive or negative) |
| * and NaN. If this returns {@code false}, that doesn't mean that it can do that, because it's maybe just that this |
| * utility doesn't know that type. |
| * |
| * @since 2.3.28 |
| */ |
| public static boolean hasTypeThatIsKnownToNotSupportInfiniteAndNaN(Number num) { |
| return num instanceof Integer || num instanceof BigDecimal || num instanceof Long |
| || num instanceof Short || num instanceof Byte || num instanceof BigInteger; |
| } |
| |
| /** |
| * Converts a {@link Number} to {@code int} whose mathematical value is exactly the same as of the original number. |
| * |
| * @throws ArithmeticException |
| * if the conversion to {@code int} is not possible without losing precision or overflow/underflow. |
| * |
| * @since 2.3.22 |
| */ |
| public static int toIntExact(Number num) { |
| if (num instanceof Integer || num instanceof Short || num instanceof Byte) { |
| return num.intValue(); |
| } else if (num instanceof Long) { |
| final long n = num.longValue(); |
| final int result = (int) n; |
| if (n != result) { |
| throw newLossyConverionException(num, Integer.class); |
| } |
| return result; |
| } else if (num instanceof Double || num instanceof Float) { |
| final double n = num.doubleValue(); |
| if (n % 1 != 0 || n < Integer.MIN_VALUE || n > Integer.MAX_VALUE) { |
| throw newLossyConverionException(num, Integer.class); |
| } |
| return (int) n; |
| } else if (num instanceof BigDecimal) { |
| // [Java 1.5] Use BigDecimal.toIntegerExact() |
| BigDecimal n = (BigDecimal) num; |
| if (!isIntegerBigDecimal(n) |
| || n.compareTo(BIG_DECIMAL_INT_MAX) > 0 || n.compareTo(BIG_DECIMAL_INT_MIN) < 0) { |
| throw newLossyConverionException(num, Integer.class); |
| } |
| return n.intValue(); |
| } else if (num instanceof BigInteger) { |
| BigInteger n = (BigInteger) num; |
| if (n.compareTo(BIG_INTEGER_INT_MAX) > 0 || n.compareTo(BIG_INTEGER_INT_MIN) < 0) { |
| throw newLossyConverionException(num, Integer.class); |
| } |
| return n.intValue(); |
| } else { |
| throw new UnsupportedNumberClassException(num.getClass()); |
| } |
| } |
| |
| private static ArithmeticException newLossyConverionException(Number fromValue, Class/*<Number>*/ toType) { |
| return new ArithmeticException( |
| "Can't convert " + fromValue + " to type " + ClassUtil.getShortClassName(toType) + " without loss."); |
| } |
| |
| } |